The invention relates to a device for measuring the rotational angle of a rotatable shaft, in which two sinusoidal signals, phase-shifted with respect to one another, are produced and the rotational angle is determined from the measured values of the signals, with the sinusoidal signals being standardized prior to the first measurement, and a device for working the method.
With such a device, the sinusoidal signals are subject to fluctuations in amplitude which are caused for example by aging or by responses to temperature changes of the parts used. For this reason, in known methods that use the measured values for arc sine and arc cosine functions to determine the measured rotational angle, the standardization is also repeated during the ongoing measurements. This is achieved for example by measuring an extreme value for one signal when it is determined that the other signal is passing through zero. The arc sine and arc cosine functions and the additional standardizations each require costly, complex, and hence time-consuming calculations.